Dan Chen, Darkhan,

On Jan 26, we looked at noise in the DGS outputs for PcalY.

There was some noise in the channels for PcalY Exc1 and Exc2: about 0.5 Vpp at ~100 kHz.

With the resistor-filters attached to the DB9 port on the AI chassis, these oscillations became more sinusoidal in shape.

After that we measured PSDs of the OFS error point and the output (also, OFSPD output with the laser turned off) with and without the resistor-filters. We did not see much change in the noise level.

Details will be posted on the wiki page: https://dac.icrr.u-tokyo.ac.jp/KAGRA/DAWG/CAL/PCAL/exp_KAGRA/210126